It is know that approximately 0.1–0.3% of donated blood units are bacterially contaminated. Although this percentage is much higher than blood contaminated by viruses, such as HIV, nevertheless no routine test is currently performed to detect bacterial contamination. This poses a serious problem because a severely contaminated blood unit can cause sepsis in a recipient.
In general, blood is sampled from the vein for viral contamination-testing and typing after completion of donation. However, it is generally believed that the bacterial contamination stems from skin-embedded bacteria inaccessible to the sanitizing agents normally used before venipuncture. Therefore, systems have already been proposed in the prior art wherein a first volume of blood, typically in the order of 25–50 ml, is sampled to determine blood type and to detect for the presence of viruses. The sampling volume washes away most of the bacterial contamination before the blood is collected in the donor bag.
Such a system should satisfy the following criteria:    1. The sampled blood should not be anticoagulated    2. The collected blood must be anticoagulated.    3. Neither the donor nor collected blood should be exposed to the atmosphere during sampling.    4. The system should be simple and user friendly.
FIG. 1 illustrates a prior art predonation system, commercially available from NPBI, Netherlands. This system includes a small sampling bag 10 (with a volume of 30–50 ml) attached to a tubing branch 12 connected via a Y-connector 14 between a donor needle 16, attached to an upstream tube 32, and a main collection bag 18. Satellite bags 17 and 19 may be connected to bag 18 for processing the blood after collection. A needle 20 is attached to the distal side of sampling bag 10 through which blood is withdrawn while the rest of the system is isolated therefrom by means of external clamps 22 on tubing branch 12 and a donor tube 24 leading to main collection bag 18.
As stated above, the sampled blood should not be anticoagulated, whereas the collected blood must be anticoagulated. Accordingly, an anticoagulant used in collection bag 18 must be prevented from entering sampling bag 10. This means that tubing branch 12 must be sealed at all times before donation. This is achieved by means of a breakaway cannula 26 which is an externally openable closure in tubing branch 12 leading to sampling bag 10.
In the prior art system, the following steps are performed:    1. Clamp donor tube 24.    2. Break breakaway cannula 26.    3. Perform venipuncture and collect first blood in sampling bag 10.    4. Clamp tubing branch 12.    5. Open donor tube clamp 22.    6. Collect blood in main bag 18.    7. Connect a vacuum tube holder to needle 20.    8. Sample blood from sampling bag 10.
Another prior art system that operates in a similar manner is commercially available from Macopharma, France. Although the prior art systems approximately satisfy the four criteria mentioned hereinabove, nevertheless, they are labor intensive and cumbersome.
Various types of apparatus and techniques for blood collection and sampling are known in the art and in the patent literature.
The following patents are believed to represent the current state of the art:
U.S. Pat. Nos. 5,928,166; 5,702,383; 5,620,008; 4,774,964; 3,877,465; and Israel Patent No. 101,680.
The following PCT publications are also believed to represent the current state of the art:
Published PCT Patent Application Nos. WO 91/00115; WO 97/45714.
The following products were known prior to the date of the present invention:
Teva Medical SampLink™ System; Beckton Dickinson Vacutainer™.